Differential tension device



. 22;:1940. v J. PARGZRL. I

DIFFERENTIAL TENSION DEVICE Filed April 12, 1935' Patented Oct. 22, 1940 PATENT OFFICE DIFFERENTIAL TENSION DEVICE Joseph Pangerl, New York. N. Y., sssignor to It. Hoe a 00., Inc., New York, N. Y., a corporation ofNew York Application Aprillz, 1935, Serial No. 15,935

BGiairns.

This invention relates to a differential tension,

device for automatically controlling the feeding of a sheet or web of material, such as for instance paper from or to a roll, principally for.

I feeding the paper in printing presses from a web to the pressure and impression cylinders under constant tension.

As it is well known, the tension of ,the paper web is generally produced by the pull exerted on the paper by the cylinders, and the degree of tension varies on account of a sliding; or gliding movement or slip of the paper beneaththe driving elements. This slip is subject 'togvariations controlled by the frictional conditions, etc., met at variations in speed.

It is the principal object of my invention to provide an automatically operating tension controlling mechanism for the paper; in printing presses, thus maintaining a uniform tension in -I order to avoid injury to the web or sheet of ma- 7 terial and delays in the working of the press.

Another object of the invention is the provision of a diiierential'tension device, for printing presses in which the prevailing tension of the 18 paper web controls a means automatically compensating for any tendency of the paper to sag or to be unduly tensioned or subjectedto lateral displacement by regulating a variable drive.

A further object of my invention is the provision of a differential tension device, preferably for the paperor material in printing presses, which includes a compensation roller regulating a variable drive on a machine driven shaft-which is so connected with the drive of the press that a at times at which the tension has a tendency to slacken, it will move automatically in a direction to produce deceleration of the web, while at times at which the tension increases, it will produce acceleration of theweb, so that the tension on the material of the web is'sub'stantially uniform at all times. These movements are to be looked at as being very small diiferential variatlons and can only be theoretically considered.

In reality or practice during the operation of the or more belts. I also provide for direct transformation of an oscillating movement of the compensating element into a laterally gliding movement, adjustable within certain limits and controlling a variable web drive. Other objects concem means for adjusting the tension of the belt or belts.

These and other objects and advantages of my invention will become more fully apparent, as the description thereof proceeds, and will then 10 be more specifically defined in the appended claims.

In the accompanying drawing forming a material part of this disclosure:

Fig. l is a fragmentary top plan view of a printing press equipped with a differential tensioning device constructed according to my invention, partly in section.

. Fig. 2 is a side elevation thereof, partly in sec-' tion on line 1-2 of Figure 1. v

As illustrated, the paper web ID, from which the paper is fed by means of suitably disposed idler rollers I i I2 journalled at convenient points of the frame i! of a press, is engaged by the usual friction drive for feeding the paper. 2

This friction drive comprises an idler roller or pulley ll arranged at the outer end of an arm l4 swinging at its inner end about a shaft or pin ii. By a belt or belts l1 roller I is driven from a pulley or roller II on a shaft II, which in turn 80 is driven by means of a gear II .fromthe press drive. The belt II is also guided across a takeup roller or pulley II and an idler roller 22 on pin or shaft II.

An adjusting arrangement for' the tension of the belt or belts i1 is provided and consists of a substantially T-shaped member 23 swinging about pivot pin I! so that the position of the roller 2 i with respect to the belt may be changed and the pivotv upon which the roller II is journailed may be adjusted to a preferredpodtlon by any suitable means generally designated 24 in Iii. 1 (not shown in Fig. 2).

The spindle I! of the compensation roller It is iournalled at its ends upon rearwardly extending compensator arms 21 which may be spac apart by a brace".

The arms 21 comprise hubs or members 20 which are journalled on bushings II mounted on w the frames I! of the press, and their extreme front ends carry the weights Ii which can be suitably adjusted on said arms.

Over the shaft ll loosely extend the sleeves 32; their suitably widened outer ends are provided with feather keyways 33. for the reception of the keyed inner ends of members 23.

The sleeves 32, acting as transverse screw feeds, fixedly carry near their widened parts the cams '34 and 35 respectively, which are formed with obliquelyor helically disposed slots 33. The headed pins or pegs 31 extend from the frames I3 and are slidably engaged in slots 38.

The inner ends of the sleeves 32 are'longltudinally fixedly but rotatably engaged by way of ball bearings 33 in recesses at the ends of each of thehalves or parts 33 of the bi-partite pulley I3. The parts 33 of the pulley I! are nonrotatively keyed upon shaft I! by means of the feather keyway 40 or the like.

In operation, any deviation from the uniform tension of the paper web will raise or lower roller 26, thus rocking or oscillating arms 21, hubs 29 and likewise sleeves 32. But, when thus rocked, the sleeves 32 are moved away from or towards each other, this transverse movement being caused and forced by the stationary pins- 31 enga'ged in slots 33 of cams 34 and 35 respectively.

The bi-partlte pulley i3 rotates with shaft I! at the speed, at which said shaft is driven by gear 20. While the conical parts or halves 39 of the bi-partite pulley are thus not affected in their rotation by the said oscillating or rocking of parts 26, 21, 23 and 32, they participate in the transverse movement of the sleeves 32, being respectively endwise connected with said sleeves. When the sleeves move towards each other, the halves 33 of pulley l3 move likewise, the effective driving diameter of the bi-partite grooved pulley being increased, so that belt I! is tighened; and its speed, as well as the speed at which it drives web I0, is also increased. Conversely, when the sleeves 32 are moved away from each other, the halves 39 of pulley l3 part likewise, so that belt I! slackens and is driven at less speed, driving web ill at less speed also. The speed at which web I is driven, is therefore an immediate function of the rocking of roller 28.

It will be understood that I have described and shown the preferred form of my invention only as an example of the many possible ways to practically construct the same, and that I may make such changes in the general arrangement of elements and in the construction of the minor details-of the device as come within the scope of the appended claims without departure from the spirit of my invention, and the principles involved.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a press, a support for a roll of material, a driving shaft mounted on the press, a variable size pulley mounted on said shaft and adapted for rotating said roll, means guiding said material through said press, a compensating tension roller adapted to rest on said guided material, a compensator arm fulcrumed concentrically with said shaft in said press and carrying said roller, and

a cam interconnecting said arm and said pulley and converting in screw feed fashion an oscillating movement imparted to said arm by the roller raised and lowered by the material it rests on into a cross movement of said cam and pulley in the direction of the axis of said shaft.

2. In a press, aframe, a driving shaft mounted said shaft when oscillated, a compensator arm angularly fixedly connecting to said sleeve, and a roller carried by said arm and adapted to rest on material extending from said roll through said press.

3. In a press, a device for feeding material from a web roll comprising a belt adapted to engage said web roll, a bi-partite pulley with relatively movable cones carrying said belt, so that the effective diameter at which said pulley engages said belt is increased and decreased as said cones are moved towards and away from each other, respectively, a screw feed operatively engaged upon one of said cones, an arm extending from and actuating said screw feed, and a roller on said arm adapted to rest upon said material at a point removed from said web roll. I

4. In a press, a device for feeding material from a web roll comprising a belt for rotating said web roll, a bi-partite pulley with relatively movable cones. carrying said belt, so that the ef fective diameter at which said pulley engages said belt is increased and decreased as said cones are moved towards and away from each other, respectively, a screw feed arranged concentrical- 'ly with and operatively engaged upon one of said cones, an arm extending from and actuating said screw feed, and a roller on said arm adapted to rest upon said material extending from said web roll.

5. In a device for feeding the material of a web 40 roll through a press, a driving shaft, a grooved pulley mounted on and driven by said shaft and comprising two cones which form the groove of the pulley and are relatively movable on said shaft, cams operatively connected with said a terial at a point removed from said web roll and 50 to be raised and lowered by .said material, and arms supporting said roller and operatively connected with said cams.

6. In a device for feeding the material of a web roll through a press, a belt engaging said web roll, a. driving shaft, a grooved pulley driving said belt, mounted on and driven by said shaft and comprising on one side of the groove a cone engaging said belt, angularly fixed but axially movableon said shaft and changing the effective diameter of said pulley when moved upon said shaft, a rocker arm fulcrumed in said press concentric with said shaft, a sleeve and cam axially movably but nonrotatably engaged upon said rocker arm and axially unmovably but rotatively engaging'said cone, and means stationary on said press, engaged upon said cam and controlling the axial movement of said cone when said arm is rocked.

JOSEPH PANGERL. 

